Field of the Invention
This invention relates to a drive device for at least one sunshade which is intended for the surface of a motor vehicle roof to be darkened. The drive device includes a pull element to which the free end of at least one sunshade is attached, and each sunshade can be wound onto a winding roller.
Description of Related Art
In one such drive means, each winding roller conventionally is mounted on a carrier so that position deviations of the winding rollers can occur.
Generally, the guided ends of the pull element are located in guide rails. In one embodiment in the art, the guided ends are each connected to a drive cable, and the two drive cables are then driven by a pinion which is actuated by a geared motor. This arrangement can result in position deviations in which the pull element is generally not accurately positioned in the transverse plane to the lengthwise axis of the motor vehicle, and is not parallel to the axis of each winding roller and the free end of each sun shade.
This lack of parallelism leads to differences between the stresses exerted on the side edges of the sunshade so that the sunshade, when in the extended position, tends to undulate or warp.
The result also occurs when the pull element is manually actuated using a handle which is located essentially in the middle of the pull element.
The object of this invention is to avoid the disadvantages of the conventional drive devices and set forth a drive device of the aforementioned type which enables uniform drawing of each sunshade and thus uniform tensioning of the material of each sunshade over its entire width.
This object is achieved in a generic drive device of the invention in which the drive device has at least one mounting rod which is mounted to be capable of swiveling with respect to the pull element and to which the free end of at least one sunshade is attached.
As a result, in the situation in which any lack of parallelism may occur between the pull element and the axis of the winding roller of each sunshade, the mounting rod can swivel relative to the pull element in order to substantially or completely balance this lack of parallelism and to enable as uniform as possible tensioning of the material of each sunshade.
Preferably, for each sunshade there is one mounting rod to which the free end of the sunshade is attached and which is pivotally mounted on the pull element.
Additionally, when the sunshades are positioned in different planes to match the arched shape of the surface of the motor vehicle roof to be darkened, accordingly the pull element is essentially arched such that the free head space in the motor vehicle is less restricted by the drive device, particularly when the motor vehicle roof is substantially arched. Preferably, the arch is formed around the lengthwise axis of the motor vehicle.
In another embodiment, multiple sunshades can extend in different planes in order to match the arched shape of the front and the rear edge of a roof opening holding a movable cover. In this embodiment, the pull element is arched accordingly.
Preferably each mounting rod is supported to be able to swivel around a swiveling axis which is essentially perpendicular to the plane of the corresponding sunshade.
In each of the embodiments of the invention, the surface of the motor vehicle roof to be darkened is independent of the roof construction and can be a transparent roof section, a transparent cover which has been inserted securely into the roof, or a roof opening which can be closed by means of a movable transparent cover, for example, a sliding roof cover.